In operating grinding machines to grind multiple workparts in succession, the size of the grinding wheel changes during the grinding run or new grinding wheels must be used in succession to replace previously worn grinding wheels during the run. In either case, it is important that the machine control unit know the size of the grinding wheel during the grinding run to make sure all moves of the grinding wheel are clear and will not hit other objects on the machine such as the wheel dresser or other workparts, to dress off approximately the correct amount when the wheel is brought to the dresser, to grind off approximately the correct amount in the event the wheel is brought to the workpart without first having been brought to the dresser and to command the wheel motor to run at the proper RPM for the desired surface speed of the wheel.
The computer control unit of flexible grinding centers having an automatic grinding wheel changer which mounts new wheels in succession as they are needed for a particular grinding operation or to replace a previously worn wheel require knowledge of the size of the grinding wheels for the above-stated reasons.